32A 240 V double pole (DP) main switch — a rewireable switch fuse unit that isolates a single-phase supply; its fuse wire is the only protection it gives.
- Double pole (DP): switches both lines of a single-phase supply together.
- Rated 32A at 240 V — for single-phase mains and heavier single-phase loads.
- Rewireable fuse protection: fuse wire blows on a heavy overload or short circuit.
- Side-operated handle — switch the supply off without opening the cover.
- For single-phase supplies only — three-phase supplies need a TPN main switch.
- No trip and no earth-leakage protection — add a 30 mA RCCB for shock protection.
- Fuse wire must match the circuit — never thicker wire or copper strip.
A main switch of this type — also called a switch fuse unit, SFU or DP main switch — puts an on/off switch and rewireable fuse protection in one enclosure. The side handle disconnects both lines of a single-phase supply together, so the wiring after it can be worked on safely.
Its only protection is the fuse wire: on a heavy overload or short circuit the wire melts and must be replaced. It does not trip like an MCB and gives no protection against earth leakage or electric shock, so pair it with a 30 mA RCCB and MCBs in the distribution board.
At 32A and 240 V it suits the incoming main of a single-phase home or shop, or a heavier single-phase load such as a pump or machine. For small loads, see our 16A 240V SPN main switch; for three-phase supplies, our TPN main switches.
Where to use it
- Incoming main switch of a single-phase home, flat or shop.
- Local switch and fuse for a single-phase pump, motor or machine.
- Sub-main switch for an outhouse, terrace room or rented portion.
- Replacing an old 32A DP main switch like for like.
How to install
- Isolate the incoming supply (the supply company's cut-out or the upstream switch) before working.
- Fix the unit upright on a wall or board, with room for the side handle to move.
- Connect the incoming supply and the outgoing cable to the terminals as marked inside the unit.
- Fit fuse wire of the correct rating on the phase side only; the neutral must never carry fuse wire.
- Earth the enclosure and close the cover before switching on.
Electrical work should be done by a licensed electrician. Re-wire a blown fuse only with the supply off, using fuse wire of the correct rating — never thicker wire or copper strip.
Frequently asked questions
- What does DP mean on a main switch?
- Double pole: the handle switches both lines of a single-phase supply together, so the circuit after it is completely disconnected.
- Should the neutral have a fuse?
- No. Indian safety regulations do not allow a fuse in the neutral conductor, so fuse wire goes on the phase side only and the neutral runs through a solid link.
- Why must the fuse wire match the rating?
- The fuse wire is the only thing protecting the cable. Wire that is too thick, doubled up or replaced by a copper strip will not blow on a fault, and the cable can overheat and catch fire.
- DP or SPN main switch — which one?
- Both are for single-phase 240 V supplies. An SPN switch fuse has a fused phase and a neutral link; a DP switch breaks both lines together. This 32A DP suits bigger loads than our 16A SPN switch.
- Main switch or DP MCB — which is better?
- An MCB trips on overload and short circuit and simply resets; a switch fuse unit needs its fuse wire replaced after a fault. Both are used as main switches — whichever you choose, add an RCCB.
Buy 32A DP main switches online from Electric Market, Chennai. For site, contractor or bulk quantities, contact us for a quote.